Yes, I have seen what appeared to be objects, which seemed to be flying, which I could not identify.
These see to be, therefore, by definition: Unidentifed Flying Objects (UFO).
Doesn't mean they have anything to do with ET, Aliens, Little Green Men, Greys, Men In Black, Bug Eyed Monsters, or any other such ... just that I couldn't identify them.
Logically . . .
evidently . . .
all such factors
do NOT PRECLUDE their having something to do with so called “ET’s” etc. etc. etc.
either.